Sliding panels exist in several different forms. As used herein, the term “sliding” shall include, without limitation, rolling on wheels or the like. Furthermore, the term “panel” shall encompass the entire structure, including any frame and objects it supports, that moves across an opening in a wall, including, without limitation, windows and doors. The frame of the panel includes at least two spaced apart exterior surfaces, which may be planar or three-dimensional curved surfaces.
A common type of automated sliding panel is the automatic sliding door frequently found in supermarkets and other retail stores. When a sensor, typically a pressure sensor in the floor or a motion sensor above the door, detects the presence of a person in front of the door, the door opens. Generally the panel is slid open by an electric motor contained in a housing external to the door. The housing may be affixed to the wall above the doorway or built into the wall. The motor drives a belt, also contained in the housing, which is attached to the sliding panel, such that rotation of the motor causes translation of the panel.
A significant disadvantage of this design is the requirement of an external housing for the motor and drive system. An external housing is aesthetically disruptive if affixed to the wall above the door. While this may not be significant in some commercial or industrial settings, it is undesirable in residential or high-end commercial settings. Although it is possible to conceal the housing by installing it inside the wall, this is also undesirable because the housing is not easily accessible for maintenance.
Another example of an existing automatic sliding panel is an automatic gate commonly used on driveways or private roads. In this design, unlike the one previously discussed, the motor and drive system are carried along with the panel as it translates. The motor drives a drive train which rotates a wheel mounted on the bottom edge of the panel. However, the motor and drive system are not built into the panel, but rather are enclosed in a housing affixed to an outer surface of the panel. This external housing is a disadvantage of the design because it is not aesthetically pleasing and thus prevents it from being a solution for automation of indoor panels.
A disadvantage of most traditional sliding panels, including automatic sliding doors, is the poor seal between the bottom surface of the panel and the surface upon which it is sliding. The bottom surface of the panel cannot make contact with the surface upon which it is sliding because the friction between those surfaces would prevent efficient movement. To overcome this problem, sliding doors have been designed such that the bottom surface of the door, when in the closed position, makes contact with the surface supporting the door. To overcome the problem of friction, the door is first lifted to a raised position to eliminate friction between the bottom surface of the panel and the support surface, and then slid open. After the door closes, it is lowered down to make a relatively weather tight seal.
A disadvantage of the lift and slide design is the difficulty of automating it. An automatic lift and slide panel must be capable of automatically raising, lowering, sliding open, and sliding closed. Because there are more components in an automatic lift and slide panel than there are in a non-lifting automatic sliding panel, it is even more difficult to fit them all inside the panel frame. This problem is magnified by the large amount of force required to raise a heavy panel off the support surface. As lift and slide panels are frequently used in applications where aesthetics are a paramount concern, it is extremely undesirable to have any externally mounted components or substantial protrusion of internal components.
Thus, although powered sliding panels and lift and slide panels are well known, the difficulty of fitting all of the required components into a relatively narrow panel frame has prevented any previous panel from being internally powered and driven. This is particularly true for lift and slide panels, which require a power source and drive system capable of exerting substantial forces. Although existing automatic panels are functional, they are not aesthetically pleasing and therefore they are not a good option for use in applications where aesthetics are important. Accordingly, there is a need for an improved sliding panel, both lifting and non-lifting, in which the power source and drive system is contained internally.